1. Field of the Invention
The present invention relates to a method of manufacturing a liquid crystal display device.
2. Description of the Related Art
In manufacturing a liquid crystal display device, after rubbing treatment is performed on alignment films respectively formed on the inner surfaces of a pair of substrates, a seal member for joining the pair of substrates is printed on the inner surface of one of the substrates by screen printing using a screen which masks a non-print area and a squeegee which is brought into contact with the screen and moved in a predetermined direction. In this case, during printing of the seal member, the surface of the alignment film which has undergone rubbing treatment is partially worn by the screen.
In order to solve this problem, for example, a method of manufacturing a liquid crystal display device is disclosed in Japanese Patent No. 2774714. In manufacturing a liquid crystal display device such as a TN or STN liquid crystal display device in which the liquid crystal molecules of a liquid crystal layer are twisted/aligned between a pair of substrates by performing rubbing treatment on the alignment films formed on the inner surfaces of the pair of substrates in directions crossing each other at a predetermined angle, according to this method, even if the surface of an alignment film which has undergone rubbing treatment is partially worn by the screen, the influence of this wear on the twist alignment of the liquid crystal molecules is prevented by performing screen printing of the seal member while moving the squeegee in a direction crossing the rubbing direction of the alignment film formed on the substrate on which the seal member is printed at an angle larger than 90°.
The conventional manufacturing method, in which a seal member is printed by moving the squeegee in a direction crossing the rubbing direction of an alignment film at an angle larger than 90° as described above, is effective in manufacturing a liquid crystal display device having liquid crystal molecules twisted/aligned. However, in manufacturing an untwisted/aligned liquid crystal display device in which the molecular long axes of the liquid crystal molecules of a liquid crystal layer are aligned with the rubbing directions of the alignment films respectively formed on the opposed inner surfaces of a pair of substrates by performing rubbing treatment on the alignment films in parallel directions, the difference between the rubbing direction of each alignment film and the direction in which the film is worn by the screen influences the alignment of the liquid crystal molecules to disturb the alignment of the liquid crystal molecules.